i'm extremely picky about mine. if i don't get past the first 5 pages, it's not even worth reading. and really, if i can't past the first one wtihout yawning, i don't even bother giving it a chance. the art has to be good or else i lose interest. if it's a romance and the art is so ugly, i don't wanna see their ugly faces snogging each other. yuck! i like simple art (like in book of friends) but then i like really detailed art too (like in trinity blood).
i can't be readin a manga and if i think "oh such-and-such is gonna happen next" and it does, then i'm done reading it. i hate predictable manga. i hate manga with love triangles in them. i hate manga that share the same sort of plot as a million other manga. lol. so yes...i'm so extremely picky about which one's i read.

I am extremely picky about my manga. Like when I have a test/exam coming up I read short tragedy manga. Or when it's raining I read shounen-ai or shoujo-ai. But mostly I don't read stuff like too shoujo-ey manga. I think they are pointless. Also, I prefer deep psychological or drama/tragedy variety as compared to slice of life and fluff. I enjoy a lot of shounen too. C:

I'm mostly picky when it come to the drawings/art even if the story line's good and that manga as bad read graphic i lose interest.

That's a pity A lot of manga with really good storylines have unconventional art that doesn't rub well with everyone at first. I've come to be open-minded about the graphics as long as the storyline is good (so I guess that makes me picky, too!)...usually the mangaka has a reason for choosing the drawing style that he/she does. Although I can only stomach sugary wide-eyed shoujo art for so long, especially if it's a manga about school. Ugh.